The Pulse

Death by sugar

Higher than normal blood sugar levels can kill you, even if it's not severe enough to be considered diabetes, say the experts.

Published 30/11/2006

[Image source: iStockphoto]

Got a sweet tooth? We all have; it's part of our biological make up. There's a theory that sugar was actually very rare in the diet of primitive homo sapiens. If you came across something sweet  honey for example  you ate it whether you were hungry or not. Most mammals, humans included, will eat sweet things anytime, hunger or not. (Cats are the exception  they aren't able to taste sugar.)

But these days, sugar is as close as the nearest vending machine, street corner kiosk or petrol station cash register. We have as much as we possibly want.

The irony is, we don't actually need any sugar. What we do need is glucose  it's the major source of energy our body uses to drive our metabolism, to keep our cells functioning. But we get it from complex carbohydrates in our diet  long chains of glucose molecules found in grains, fruit and vegetables  that are broken down in the gut into glucose molecules, and gradually absorbed into the blood.

But sugar is a 'simple' carbohydrate, made of a glucose molecule joined with a fructose (a fruit sugar) molecule  it breaks down and is absorbed quickly into the bloodstream. Levels of glucose rise quickly, and reach higher levels than if we got our glucose from complex carbohydrates.

Because there's now so many sugar-laden foods around, and we have an insatiable desire for sweet things, our blood sugar levels are dangerously high  killing millions of people worldwide every year.

That's the finding of researchers from Harvard University in the US who looked at population health surveys and reviews of studies from 52 countries around the world over the last fifteen years; studies looking at the health of people with raised blood sugar.

Heart disease and stroke

For reasons we don't fully understand, high blood glucose makes it more likely a person will develop atherosclerosis  the 'gumming up' of the arteries that causes heart disease and stroke, the major worldwide killers.

The researchers calculated that raised blood glucose accounts for 21 per cent of ischaemic heart disease and 13 per cent of stroke mortality worldwide  3.16 million deaths a year. They say deaths from high blood sugar are three times higher than those caused by full-blown diabetes  the condition we usually associate with high blood sugar.

It's a particular problem in low- and middle-income nations, especially the Middle East, North Africa, South and East Asia and in the Pacific, say the researchers. These populations have only recently, in evolutionary terms, become exposed to a high sugar diet; their metabolisms aren't used to it. And to compound the problem, there isn't much in the way of prevention and treatment programs in these regions.

But blood sugar levels are on the rise in developed countries too, fuelled not only by our high sugar intake, but our sedentary lifestyles  the less we exercise, the fatter we get, and this makes our body less able to metabolise sugar, so our blood sugar levels rise even further.

What's the solution? The researchers call for a more aggressive approach by governments to tackle the problem; public health programs aimed at changing our dietary habits, and tightening of regulations governing labelling, marketing and food manufacturing processes.

But there's been stiff resistance to the idea of more regulation from Australian and international food companies, advertisers, and governments who argue that it's up to consumers to make informed choices about their diet. If people know sugar is bad, don't eat sugar, is the attitude.

But this is easier said than done. It's easy to pick some foods as being high in sugar - syrups, jams, marmalade, sweets, soft drinks for example. But in fact most of our sugar comes from manufactured and processed foods like pies, pastries, desserts, and ice cream, and it can be hard to know whether they contain sugar and how much.

Since 2002, it's been mandatory in Australia for manufacturers to include a detailed breakdown of the product's nutritional status on the packaging.

They have to carry a label indicating how much sugar the product contains, as well as levels of energy in kilojoules, protein, total fat, saturated fat, carbohydrate, sugars and salt per serve and per 100g of food, or 100ml for liquids.

How much is a lot? Two or three grams of sugar per 100 grams is a low sugar product, 30 grams or more is chock full of sugar.

Manufacturers also have to list the ingredients in order of weight. Ingredients high in sugar (though you way not realise it) include corn syrup, dextrose, honey, mannitol, maple syrup and sorbitol.

So the idea is, read the labels, determine the sugar content, make your own decisions.

Confusing and innaccurate labels

If only it was that easy. Consumers complain that that this labelling system is confusing; they don't know what these numbers really mean and how to use them. How many grams am I eating? How much sugar does it all add up to? Is that too much? What about fats? Calories etc etc?

Some nutritionists and consumer groups are calling for a simplified rating system like a traffic light system (for example green for low sugar, red for high sugar)  a system like this is in place in the UK.

We also now know that the information on the labels is just plain wrong, thanks to a study published in this month's Asia Pacific Journal of Clinical Nutrition.

Researchers from the NSW Food Authority looked at 350 samples of 70 different products for nutritional compounds declared on the label, and big differences on what the label said and what was in the foods. They found variations in ingredients compared to the stated amounts on the label of between 13 per cent less to 61 per cent.

They say there's no requirement in Australia for manufacturers to be accurate about the stated amounts. Overseas, some countries' regulatory authorities allow an error of 20 per cent either way.

But the survey revealed only 16 per cent of the products tested fell within a 20 per cent margin of error.

Food Standards Australia New Zealand says it's going to look at food manufacturer's compliance with labelling requirements in more detail next year.

But whether there's more or less sugar than the manufacturer claims, refined sugar is more dangerous than we imagine. It's better to get your glucose from complex carbohydrates  fruit, vegetables, and grains  and avoid processed and sweetened foods. Life's just fine without them. You don't hear your cat complaining.